基于SNGAN的黑盒恶意软件对抗样本生成方法

目前，为了应对数以百万计的Android恶意软件，基于机器学习的检测器被广泛应用，然而其普遍存在防对抗攻击能力差的问题，对恶意软件对抗样本生成方法的研究有助于促进恶意软件检测领域相关研究的发展.黑盒场景下的对抗样本生成技术更加符合现实环境，但相较于白盒场景效果不佳.针对这一问题，本文提出了一种基于SNGAN的黑盒恶意软件对抗样本生成方法，将图像领域的SNGAN方法迁移到恶意软件领域，通过生成器网络和替代检测器网络的迭代训练生成对抗样本，并通过谱归一化来稳定训练过程.该方法能够对已有的恶意软件添加扰动，达到欺骗机器学习检测器的效果.实验结果证明，该方法对多种机器学习分类器均可以有效规避检测，验证了方法的可行性和可迁移性.     

基于深度卷积神经网络的脑电图异常检测

为解决EEG自动检测的错误率非常高的问题,提出了一种基于深层卷积神经网络(CNN)对脑电图进行异常检测的方法:首先,对多个异构数据源按标准进行重构和预处理,生成了有118 716个样本的训练集和有12 022个样本的测试集;然后,构建有快捷连接的深层CNN模型,以自动化学习ECG特征并进行分类识别; 接着,将模型在训练集上进行试验与调参,保存了性能最好的模型参数; 最后,在测试集上进行预测.预测结果显示该模型达到了94.33%的分类准确率.通过所提方法对脑电信号进行处理与分析,能够自动提取EEG特征并进行异常识别,从而达到快速检测与辅助诊疗的目的.     

基于深度主动学习的甲状腺癌病理图像分类方法

甲状腺癌是内分泌系统最常见的恶性肿瘤,甲状腺病理图像对于甲状腺癌的分级、预后和后续治疗有重要的指导作用.近年来,深度学习在病理图像分类分级中表现出色,然而,为了获得良好的分类性能,这些方法往往需要大量的标注数据.众所周知,医学图像的手动注释非常繁琐、耗时,并且需要领域知识的指导.为了降低标注成本,提出一种将卷积神经网络(Convolutional Neural Networks,CNN)和主动学习相结合的分类方法,无须标记所有数据,仅选择少量样本进行标注.此方法利用CNN提取病理图像的特征,进而使用该特征计算未标注样本的不确定性和相似性,选择"有价值"的样本;然后由病理学家对选定的样本进行标注,并不断微调网络以增强模型的分类性能.在甲状腺病理图像上的实验结果表明,该方法能够在不牺牲最终分类准确率的情况下降低标记成本.     

图像分类卷积神经网络的进化设计

为解决图像分类中深度卷积神经网络(Convolutional neural networks,CNN)中较为复杂的人工网络设计与调参问题,提出基于ResNet模块的进化卷积、神经网络(Evolutionary convolutional neural network,ECNN)的自动设计方法,并将其运用到图像分类中.该方法基于ResNet模块与2D卷积层,采用进化算法(Evolutionary algorithm,EA)对网络结构及参数进行优化.在NLM官方发布的疟疾数据集下进行实验,不同比例的测试集划分可以达到95.6%的分类准确率,文中算法与AlexNet、VGG16、Xception等人工设计的深度学习分类算法进行了比较,实验结果表明,其准确率提升了约1%.在斯坦福大学发布的Stanford cars车辆图像数据集中进行了算法泛化验证,结果表明,文中算法在不同比例数据的测试中准确率均在94.5%以上,将该算法与深度学习分类算法VGG16进行比较,准确率效果相当,模型测试图像分类耗时仅为VGG16耗时的1/13,且训练参数量较少.两组对比测试实验数据表明,相比人工设计的深度学习算法,本文方法具有较好的图像分类性能与较快的图像分类速度.     

基于图像去噪和图像生成的对抗样本检测方法

针对现有对抗样本检测方法存在检测准确率低和训练收敛速度慢等问题,提出一种基于图像去噪技术和图像生成技术实现的对抗样本检测方法.该检测方法将对抗样本检测问题转换为图像分类问题,无须事先得知被攻击模型的结构和参数,仅使用图像的语义信息和分类标签信息即可判定图像是否为对抗样本.首先,采用基于swin-transformer和vision-transformer实现的移动窗口式掩码自编码器去除图像中的对抗性噪声,还原图像的语义信息.然后,使用基于带有梯度惩罚的条件生成式对抗网络实现的图像生成部分根据图像分类标签信息生成图像.最后,将前两阶段输出的图像输入卷积神经网络进行分类,通过对比完成去噪的图像和生成图像的分类结果一致性判定检测图像是否为对抗样本.在MNIST、GTSRB和CIAFAR-10数据集上的实验结果表明,相比于传统检测方法,本文提出的对抗样本检测方法的平均检测准确率提高6%~36%,F1分数提高6%~37%,训练收敛耗时缩减27%~83%,存在一定优势.     

基于网络流量分析的未知恶意软件检测

为了有效检测移动端的未知恶意软件,提出一种基于机器学习算法,并结合提取的具有鲁棒性的网络流量统计特征,训练出具有未知移动恶意网络流量识别能力的检测模型;该模型主要包括Android恶意软件样本数据预处理、网络流量数据自动采集以及机器学习检测模型训练;通过对不同时间节点的零日恶意软件检测的实验,验证模型的有效性。结果表明,所提出的方法对未知恶意样本的检测精度可以超过90%,并且F度量值为80%。     

基于距离度量学习的SAR图像识别方法

针对合成孔径雷达（synthetic aperture radar,SAR）图像样本数据有限,且不同类别间的图像区分度不高导致识别困难的问题,提出一种应用于SAR图像识别的距离度量学习方法.该方法使用CNN网络得到图像的特征分布,利用LSTM网络加强图像间的关联性,基于余弦相似距离度量方法计算图像之间的匹配度,通过注意力机制后对结果进行分类.训练过程结合小样本学习的训练方式,采取预训练的策略进行实验.实验以公开的MSTAR数据集进行SAR图像识别,结果表明该方法准确率达到99.3%,比SVM方法提升2.5%.      

基于CNN-GCN模型的扫描电镜图像分类

通过对矿物扫描电镜图像进行分类与鉴定，能够获取矿物的微观信息，确定矿物的组成与类别，对于油气田生、储、盖类型的研究具有重要的意义.由于在一幅图像之中有时不止有一种矿物，且不同矿物之间具有相关性或共生性的特性，而普通的神经网络只提取图像特征或只注意图像局部的特征关系，忽略了矿物之间的相关性.因此如何利用标签之间的关系进行更优秀的多标签图像分类成为扫描电镜图像分类的重要任务.鉴于上述情况，通过构建基于Resnet50的图像特征学习模块与基于图卷积神经网络的分类器模块构成的引入图卷积的卷积神经网络模型可以很好地完成上述任务.使用卷积神经网络模块提取图像特征，并利用GCN模块学习矿物标签之间的相关性，达到提高分类准确率的目的 .此模型相比普通的CNN模型准确率提高了5%，相比引入注意力机制的CNN模型，此模型的准确率仍有3%的优势.实验表明，CNN与GCN相结合的分类模型在扫描电镜数据集分类任务中优于其他的分类模型.     

DBN和GRU混合的Android恶意软件检测模型

针对Android平台恶意软件数量增长迅猛,种类日益增多的现状,提出了一种基于深度置信网络和门控循环单元网络混合的Android恶意软件检测模型。通过自动化提取Android应用软件的特征,包括权限等静态特征和应用运行时的动态特征进行训练,对Android恶意软件进行检测和分类。实验结果表明,混合了门控循环单元网络和深度置信网络的混合模型,在检测效果上优于传统的机器学习算法和深度置信网络模型。     

一种基于注意力导向CNN的晶粒缺陷检测方法

针对半导体生产过程中的晶粒缺陷检测任务,提出了一种融入多头注意力机制的新型CNN模型(AttnNet).该模型使用深度可分离卷积和标准卷积累加的卷积结构提取输入图像特征,借助多头注意力机制更新特征权重,输出注意力机制筛选的图像分类结果.在13 513张晶粒图像构成的数据集上训练、验证及测试,并与VGG-16、ResNet-50和MobileNet-v2进行对比.相较于现有经典CNN网络模型,Attn-Net检测用时更短(1.26 s),模型尺寸更小(25 MB),在测试集上的分类准确率超过99%,是一种高效且轻量化的晶粒缺陷检测和分类模型.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.